BTR Waterproof High Visibility Backpack Cover, Rucksack Cover Plus Waterproof & High Visibility Helmet Cover Backpack Cover is made from 300D Oxford-coated polyester fabric with an additional PVC coating so is far more durable and waterproof than previous versions of this cover Velcro cross over straps and pull chord ensure the cover fits very securely and snugly around the WHOLE backpack. By having the vertical straps it means there isnt a gaping gab between the cover and the backpack at the top of the backpack. Fluorescent fabric provides extra daytime visibility, and reflective strips (two 3M Scotchlite Tape + extra printed highly reflective stripes) offer superb visibility for cycling in the dusk or dark to help keep you safe. High-quality, waterproof backpack cover - strong and lightweight to help make you visible and keep your backpack dry Backpack Cover Available in two sizes. MEDIUM Backpack Cover: 18.5 x 14.5 inches..... LARGE Backpack Cover: 22.5 x 18.5 inches Set also includes a waterproof and high visibility helmet cover